Hi Engineers !
I have a system which contains many end devices (cc2511) and an access point. I chose the length of the fields preamble and sync 4 byte for each field. In the case of my system , the synchronization is a crucial need. So will these fields insure the synchronization ? Or I must find a solution for this problem ?
I think that I must use a special protocol to send timestamp : So any advice Please ?
I'm wandering if someone can help me ? please answer me as soon as possible !
Your suggestion will be greatly appreciated :)
Thanks !!
houda,
I think the best option is to send a time stamp packet and on the receiving side use the interrupt flag "CRC OK" as hardware signal to get fine grained synchronization.
Regards/TA
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Hi TA !
Thanks a lot for your answer. Can you Please explain me more ?
I'm waiting for your answer :)
What is your requirement on the synchronization, what is the accuracy?
look at the CC2510 datasheet on Table 73, it discusses the various hardware signals that the RF core will send to the MCU core. These can be use for aligning your MCU timers to and thereby give you a very accurate synchronization. ( I have previously estimate the accuracy to be 4 times the used bitrate)
Say you run at 100kbps then you will get ~1 / (4*100kbps) => ~2.5us accuracy.
Regards,/TA
Thanks a lot for your help :)
In fact I haven't a precise requirement on the synchronization.
I still have some questions:
1) Do you think that to solve the synchronization problem a hardware solution will be better than a software solution ?
2) I Know that there are many protocols which are used to insure synchronization for example TPSN and FTSP so I'm wandering if I can implement a synchronization protocol with SimpliciTI stack.
Your suggestion will be greatly appreciated !!
I do not know TPSN or FTSP, but generally it should be possible for you to add a software protocol on top of SimpliciTI.
Thanks for your help and guidance :)
I decided to use sending timestamp and the interruption "CRC ok " in the receiver.
I still have a question Please: the timestamp paquet must be sent regularly : every period T. Can you give me an estimation of the value of T ?
Thanks :))))
houda
I assume you have a 32khz RTC on your design. They take the accuracy of the xtal (20-30ppm) and extrapolate it.
Say one sync packet per second => 30us error
Then you have to decide how much error you can tolerate.